Table 4.

Longitudinal Gastrointestinal Symptoms in Children With Autism Spectrum Disorder vs Children With Typical Development or Developmental Delay

Symptom	Autism Spectrum Disorder vs Typical Development			Autism Spectrum Disorder vs Developmental Delay
Symptom	OR (95% CI)	aOR^a (95% CI)	P Value	OR (95% CI)	aOR^a (95% CI)	P Value
Diarrhea
None	1 [Reference]	1 [Reference]	NA	1 [Reference]	1 [Reference]	NA
6–18 mo only	1.1 (0.8–1.4)	1.1 (0.8–1.5)	.56	1.0 (0.8–1.4)	1.1 (0.8–1.5)	.56
18–36 mo only	2.8 (1.2–6.4)	2.3 (1.0–5.3)	.05	1.9 (0.8–4.5)	1.8 (0.8–4.3)	.17
Both	2.8 (1.6–4.7)	2.4 (1.4–4.2)	<.01	2.4 (1.4–4.1)	2.5 (1.4–3.8)	<.01
Constipation
None	1 [Reference]	1 [Reference]	NA	1 [Reference]	1 [Reference]	NA
6–18 mo only	2.0 (1.3–3.2)	2.3 (1.4–3.7)	<.01	1.6 (1.0–2.6)	1.7 (1.1–2.8)	.03
18–36 mo only	1.1 (0.7–1.7)	1.2 (0.8–2.0)	.37	1.0 (0.6–1.6)	1.0 (0.6–1.6)	.99
Both	2.7 (1.7–4.4)	3.4 (2.1–5.5)	<.001	2.1 (1.3–3.5)	2.3 (1.4–3.8)	<.01
Food allergy/intolerance
None	1 [Reference]	1 [Reference]	NA	1 [Reference]	1 [Reference]	NA
6–18 mo only	1.9 (1.0–3.6)	1.8 (1.0–3.3)	.07	1.7 (0.9–3.2)	1.6 (0.9–3.1)	.13
18–36 mo only	2.6 (1.4–4.7)	2.5 (1.4–4.4)	<.01	2.1 (1.1–3.8)	2.0 (1.1–3.7)	.02
Both	2.0 (1.1–3.5)	1.8 (1.0–3.2)	.04	1.6 (0.9–2.8)	1.5 (0.9–2.8)	.14
Any GI symptom^b
None	1 [Reference]	1 [Reference]	NA	1 [Reference]	1 [Reference]	NA
6–18 mo only	1.1 (0.8–1.6)	1.2 (0.8–1.7)	.38	1.1 (0.7–1.5)	1.1 (0.8–1.6)	.50
18–36 mo only	1.6 (0.9–2.6)	1.7 (1.0–2.8)	.06	1.3 (0.8–2.3)	1.3 (0.8–2.3)	.32
Both	2.5 (1.7–3.5)	2.6 (1.8–3.7)	<.001	2.0 (1.3–2.9)	2.1 (1.4–3.0)	<.001

Abbreviations: aOR, adjusted odds ratio; GI, gastrointestinal; NA, not applicable; OR, odds ratio.

Adjustment variables include sex, year of birth, maternal educational level, maternal smoking, and breastfeeding

Any GI symptom includes diarrhea, constipation, and food allergy/intolerance.